I read all of Ken’s books, and I was an active learner who downloaded and listened to nearly all audio programs when it was still IntegralNaked.
I was introduced to Ken Wilber’s thoughts in some other books such as “Thought as Passion” by Frank Visser.
I think the first book that I read that was actually written by Ken was either Boomeritis or Brief History of Everything almost 15 years ago. Marriage of Sense and Soul is very good read because it was first of Ken’s books to be published by a mainstream publisher (big 4, random house)—it was critically acclaimed by Al Gore.
I also read One Taste and listened to Kosmic Consciousness CDs relatively early—these two knowledge products gave clear hints that Ken’s mind is just off-the-chart extraordinary. [I think he said in one of the IntegralNaked audio program that he read 23 PhD worth of books and was able to write books in his head]
I soon read all of Ken’s books that he has written in 1-2 years. I remember “Sex, Ecology, Spirituality“ and “Integral Spirituality” being more challenging books—but these two texts are also foundational because they are what started /delineated Wilber IV and Wilber V. Ken’s earlier books did contain concepts that are no longer deemed correct in current Integral theory—e.g. stacking “nature, deity, formless and nondual mysticism” on top of centauric/vision logic stage. But his earlier books contain many extraordinary quotes and very poetic writings. [Many of people I talked to are still only familiar with Ken’s earliest books such as Spectrum of Consciousness, No Boundary and Up from Eden]
Ken’s books written in the 2010s might be written without an editor involved—although I appreciate the framework, the quality of the writing has indeed dropped off compared to Ken’s earlier works written in his 20’s 30’s 40’s 50’s. (I also understand that there is often an assumption that the reader might not be familiar with AQAL theory, so there often is a fair amount of repetition in Ken’s later books) I understand that Ken is very established now and he also could have some physical limitation—so I still appreciate the new concepts that I could find in the newer books such as “Integral Meditation” and “Religion of tomorrow”. [I appreciated the description of 3rd tier, for instance—which were not really touched on in books before 2010s—, but I did have lots of questions about it]
So for me, a good order might be:
To know the theory, start with :
Brief history of everything
Marriage of Sense and Soul
Theory of Everything
Eye of the Spirit
Integral Life Practice (the book)
For deeper cut:
Sex, ecology, spirituality
fragments of 2nd Kosmos trilogy
To know the man, and why you need to understand his mind, go with:
Kosmic Consciousness CDs
Ken Wilber biography course
Ken Wilber Brainwave video on Youtube
If you want to appreciate poetic writings, go with:
Spectrum of consciousness
Up from Eden
Then read other books when you are feeling completionist like me:
for books written in 2010s, I don’t know how a total beginner would react if he or she were to read without an understanding of integral theory in the first place. Religion of Tomorrow and Integral Buddhism are the same books—the former contains the latter. So I personally think books written after Integral Spirituality are for people who are already fairly grounded in integral and would not mind some flaws in the writings but are more looking for just ideas and meta-frameworks.
I am still waiting for Kosmos Trilogy Volume 2 and 3 and waiting to see if there will be emergence of Wilber VI and VII.
May you find great mental clarity with the integral framework, and may people around you benefit from the wisdom that you manifest in the world.